Toluene diisocyanate (TDI) is produced today primarily as a chemical feed stock for reaction with polyols to form polyurethanes. One way in which toluene diisocyanate is conventionally made includes (1) nitration, which involves the reaction of toluene with nitric acid and a catalyst to form dinitrotoluene; (2) hydrogenation, in which dinitrotoluene is reacted with hydrogen and a catalyst to form a mixture of isomers of toluene diamine (TDA); (3) distillation of the TDA mixture to produce meta-TDA; and (4) phosgenation, in which the meta-TDA is reacted with phosgene to form a crude TDI mixture. The crude TDI mixture can then be distilled to isolate various molar ratios of TDI isomers, such as an 80:20 mixture of 2,4-TDI and 2,6-TDI, known as TDI (80/20). In some instances the pure 2,4-TDI and a 65:35 mixture of 2,4-TDI and 2,6-TDI, known as TDI (65/35) are isolated. Each of the isocyanate functional groups in TDI can react with a hydroxyl group to form a urethane linkage. Existing processes and production facilities for producing the toluene diisocyanate mixture, in particular, are subject to various constraints such as mass flow limitations, product yield, plant size and energy consumption. Accordingly, there is continuing interest in improving the way that toluene diisocyanate is produced.